Think how often we diagnose a person based on a casual description. Imagine you’re set up on a blind date with a friend of a friend. When the big night arrives, you meet your date at a restaurant and make small talk while you wait for the appetizer to arrive. “So,” you say, “what do you have planned for this weekend?” “Oh, probably what I do every weekend: stay home and read Hegel,” your date responds with a straight face. Because your mutual friend described your date as “smart, funny, and interesting,” you laugh, thinking to yourself that your friend was right, this person’s deadpan sense of humour is right up your alley. And just like that, the date is off to a promising start. But what if the friend had described your date as “smart, serious, and interesting”? In that light, you might interpret the comment as genuine and instead think, “How much Hegel can one person read?” Your entire perception of your date would be clouded; you’d spend the rest of dinner wracking your brain over the difference between Heidegger and Hegel and leave without ordering dessert.
Interestingly, even when we’re not given a clear-cut value tag, we are so eager to assign a value that we create our own diagnostic labels. Most of us simply can’t stay neutral for long, which is why we’re so susceptible to following the siren song of the diagnostic bias.
Each day we’re bombarded with so much information that if we had no way to filter it, we’d be unable to function. Psychologist Franz Epting, an expert in understanding how people construct meaning in their experiences, explained, “We use diagnostic labels to organise and simplify. But any classification that you come up with,” cautioned Epting, “has got to work by ignoring a lot of other things — with the hope that the things you are ignoring don’t make a difference. And that’s where the rub is. Once you get a label in mind, you don’t notice things that don’t fit within the categories that do make a difference.”
What Epting is saying is that all of us put on diagnostic glasses when we encounter new people. When we meet someone at a party, for example, we quickly diagnose him or her as “approachable” or “standoffish” before deciding whether we want to engage in a conversation.
But we pay a price for these mental shortcuts, explained Epting: “The baggage that comes with labeling is the notion of the blinders, really. It prevents you from seeing what’s clearly before your face; all you’re seeing now is the label.” An NBA player is labeled as a low draft pick. Thanks to our diagnostic bias, it doesn’t matter whether he plays his heart out: he’ll always be viewed as subpar. Once a professor is described as cold, his personality and teaching ability cease to matter: his students dislike him anyway. The diagnosis bias causes us to distort or even ignore objective data.